Appliance for automatic lathes



29, 1952 A. BECHLER 2,604,691

APPLIANCE FOR AUTOMATIC LATHES Filed Sept. 23, 1946 2 SHEETSSHEET 1 lNl/f/VTOR:

23 22 ANDRE BECHLER By K A ATTOR )4 A. BECHLER APPLIANCE FOR AUTOMATIC LATHES July 29, 1952 2 SI-IEETS--SI-IEET 2 Filed Sept. 23, 1946 E wm fl B wx My Patented July 29, 1952 UNITED STATES Paras-r ea-ea Andre Bechler, Moutier, Switzerland Application September 23, 1946, Serial No. 698,814

' In Switzerland July 23, 1946 4 Claims. 1

In automatic lathes drillingappliances with several working spindles such as tool-holders capable of being brought successively into alignment with the headstock spindle axis are used either to bore holes of different size, or to tap or enlarge a hole after it has been made. In all types of appliances of this kind known up to the present, day, the position of the working spindle, or spindle of the drill-holder, relative to the piece of Work, was controlled by a lever-arm with follower riding on the contour of a cam lobe. It sometimes happens that the surface of the cam is not absolutely clean, or is a little rough, causing an increase in the diameter of its lobe, so that alignment of the tool and the work is inaccurate.

The object of the present invention is to provide means which make the position of the axis of each working spindle independent of the state of the working surface of the cam. To this end, a tool-box containing the working spindles is adapted to be abutted by controlling levers, abutment being effected by a spring, each of these levers having a cam follower resiliently connected therewith, and each cam follower being actuated by a cam. The working range of each lever is regulated by means of an adjustable stop-screw.

The drawing shows, by way of example, an embodiment of a drilling appliance with several working spindles according to the invention.

Fig. l is a side-elevation of the appliance, partly in section along the broken line I-I in Fig. 2.

Fig. 2 is an end-elevation of the same, as seen from the back end of the lathe, partly in section along the line II-II in Fig. 1.

Fig. 3 is a plan view of the same, partly in section along the line III-III in Fig. 1.

Fig. 4 is a partial end-view of the appliance as shown in Fig. 1.

With reference to the drawing, the frame IU of the lathe, of which a portion only is represented, carries a bracket I on which the drilling appliance is mounted. The latter comprises a tool box [2, in the two checks of which working spindles such as tool holders |3, l4 and counter gears |5, |6 are rotatably mounted. Gear wheel i6 is keyed on axle I! carrying a rope pulley I8 for driving the tool holders. The tool box 2 rocks on pivots I! and I9, the latter being in the form of a gudgeon coaxial with the former and carried in a support 20 formed by the lower part of the tool box l2. A lateral arm 22 (see Fig. 2) projecting from the support 20 carries a pin 23 which is abutted by the bent ends 24 of the levers 25 pivoted on shaft 26 carried in supports 21 and 28 cast integral with the bracket Arm 22 extends opposite to the cam-shaft side of the mechanism, so that the swingaxis' 25 of levers 25 is disposed between the cam shaft 33 and the swing axis ll of the tool box.

The levers 25 are provided with followers 29 carried at the extremities of springs 30 which are secured to the levers by screws. Each follower rides on the one of the cams 3| and 32 fixed on camshaft 33 which carries a cylindrical cam 34 cooperating with a lever 35, pivoted at36. Lever 35 carries a .pin 37 for actuating the tool holders l3 and I4 when they are in alignment with the pin (see Fig. 4).

The tool box I2 is not rigidly connected with the levers 25. It is forced against the angleshaped ends 2d of the latter by a spring 38 attached, at one end, to a bolt 39 extending from bracket H, and at the other end, to an ear provided on the tool box. Stop-screws 4|, 42 are inserted in the base plate of the bracket individually, limiting the motion of levers 25.

The appliance shown in the drawing functions as follows: The rope pulley l8 revolves the tool holders l3 and I4 continuously. The cylindrical cam 34 acting through the lever 35 causes the pin 31 to axially displace one or the other of the tool holders [3 or M, i. e. the one which happens to be in alignment with it. In the drawing, I3 is shown about to be pushed into working position. For placing the tool holder It in working position, cam 32 lifts the lever 25 whose follower rides on cam 32 and lowers the end 24 of the lever for depressing pin 23 projecting from the tool box I2 and swinging the latter clockwise as seen in Fig. 2, independently of the position of the other lever whose follower rides on cam 3|. The effect of cam 32 is limited by stop screw 42 which accurately determines the operating position of spindle M. The disposition of the moving parts represented in the drawing effects exact operating position of the tool holder I3 which is independent of any roughness of the cam 3|, because of the cam presses the lever by means of leave spring 36 against the stop-screw 4| and continues to bend the spring 30 without any effect on the box, spring 38 forcing pin 23 rigidly connected with the box against the end 24 of the lever. Likewise, the combination of the invention assures independence of the operating position of spindle I4 from the cam after the spindle is in its operating position if cam 32 actuates its lever 25, whose motion is limited by the stop-screw 42.

The number of working spindles represented 3 in the drawing is two; there is no reason why this number should not be increased to some reasonable extent.

What I claim is:

1. An automatic lathe comprising, in combination, a support, a tool holder swingably mounted on said support, a shaft mounted on said support and having a rotation axis parallel to the swing axis of said tool holder, a plurality of cams mounted on said shaft, a plurality of levers, one for each of said cams, said levers being individually swingable about an axis parallel to the rotation axis of said shaft and adapted to individually abuttingly engage said tool holder eccentrically of its swing axis, each lever having a cam follower resiliently connected to it and engaging one of said cams, adjustable stop means, one for each lever, connected with said support for limiting the extent of movement of each lever, and means tending to swing said tool holder in a direction for abutting at least one of said levers.

2. An automatic lathe as defined in claim 1, in which the swing axis of said levers is disposed between said shaft and the swing axis of the tool holder.

3. An automatic lathe as defined in claim 1, comprising leave springs, one for each lever, for resiliently connecting said cam followers and said levers.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 504,102 Claussen Aug. 29, 1893 1,810,227 Shea June 16, 1931 2,345,686 Rich et a1 Apr. 4, 1944 2,348,657 Silva et a1. May 9, 1944 FOREIGN PATENTS Number Country Date 11,686 Great Britain of 1914 93,034 Switzerland Feb. 16, 1922 639,474 Germany Dec. 7, 1936 685,111 Germany Dec. 12, 1939 

